CVE-2026-45972 — smb: client: fix potential UAF and double free in smb2_open_file()
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF and double free in smb2_open_file() Zero out @err_iov and @err_buftype before retrying SMB2_open() to prevent an UAF bug if @data != NULL, otherwise a double free.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+4
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ b64e3b5d8d759dd4333992e4ba4dadf9359952c8 and < 4d339b219004869e96c4ce56b8891f83a38da4c0version 6.19≥ 6.18.10 and < 6.18.14≥ 6.12.70 and < 6.12.75≥ 6.6.124 and < 6.6.128≥ 6.1.163 and < 6.1.165≥ e3a43633023e3cacaca60d4b8972d084a2b06236 and < ebbbc4bfad4cb355d17c671223d0814ee3ef4eda≥ e3a43633023e3cacaca60d4b8972d084a2b06236 and < 639deb962986ef2f5e2a6d5a600c66f922471e81 and 3 more≥ 9ee608a64e37cea5b4b13e436c559dd0fb2ad1b5 and < e66dcf7bb9c4df5582c82bc3582725abcbfbea73≥ 3a6d6b332f92990958602c1e35ce0173e2dd62e9 and < 7425453ea16dbc3bbb0f6cac4d60b537e5e4d151≥ 743f70406264348c0830f38409eb6c40a42fb2db and < 96e53bb3ee2f354cf6b4ab07bcc56e500f8b3f74 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.1.163 and < 6.1.165version 6.19≥ 6.19.1 and < 6.19.4≥ 6.18.10 and < 6.18.14≥ 6.12.70 and < 6.12.75≥ 6.6.124 and < 6.6.128 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 9.8 | CVSS 3.1 | Critical | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 7.0 | CVSS 3.1 | High | 1.0 | 5.9 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.33%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 9.8
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
9 on the record
- git.kernel.org/stable/c/96e53bb3ee2f354cf6b4ab07bcc56e500f8b3f74
- git.kernel.org/stable/c/ebbbc4bfad4cb355d17c671223d0814ee3ef4eda
- git.kernel.org/stable/c/4d339b219004869e96c4ce56b8891f83a38da4c0
- git.kernel.org/stable/c/7425453ea16dbc3bbb0f6cac4d60b537e5e4d151
- git.kernel.org/stable/c/639deb962986ef2f5e2a6d5a600c66f922471e81
- git.kernel.org/stable/c/e66dcf7bb9c4df5582c82bc3582725abcbfbea73
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45972.json
- access.redhat.com/security/cve/CVE-2026-45972
- bugzilla.redhat.com/show_bug.cgi
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-45972 is "smb: client: fix potential UAF and double free in smb2_open_file()", rated Critical. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.33% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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